1. Field of the Invention
The present invention relates to a plug-in connector system, and a network plug and a network socket for protected establishment of a network connection, which is especially suitable for granting previously defined maintenance companies or maintenance technicians access to a system that is to be maintained.
2. Description of the Related Art
Technical devices require maintenance at regular intervals or in the event of malfunctions. To guarantee operational security, the maintenance should only be undertaken by authorized personnel. Consequently, it is necessary to allow only appropriately authorized personnel access to the maintenance functionality of the machine or system. For example, an owner of a machine can make it possible that only maintenance personnel who have completed the appropriate training have access to the machine to be maintained. Thus, on the one hand, the safety of the maintenance technician and, on the other hand, the correct operation of the machine to be maintained can be guaranteed.
In such cases, mobile maintenance devices, such as notebooks or PDAs (Personal Digital Assistants), are normally used, which obtain maintenance access by a locally accessible interface to a specific industrial device, such as a train, an interlocking system, an automation controller or a medical device. The connection to the locally accessible interface is made by wire or wirelessly. Diagnostic functions can be called up through the maintenance access, error memories read out, configuration settings of the industrial system modified or software updates uploaded.
To grant access rights, an authentication check is usually performed in which a claimed identity is verified and thus the authorization for accessing the respective maintenance interface is checked. If the authentication check is successful, the access rights previously allocated to the respective user are granted.
Most known authentication methods are based on the entity to be authorized having to prove, in relation to a checking entity, that it is in possession of a secret and/or of an object. The best known authentication method is the transmission of a password in which the authenticating entity transmits a secret password directly to a checking entity. The checking entity or the authentication checking unit respectively then check the correctness of the transmitted password.
For administration of maintenance accesses in large systems, however, such a method involves a significant administrative overhead. In particular, when temporary maintenance technicians or freelancers are used, the respective maintenance passwords should be changed again once maintenance on the system to be maintained has been completed so that future maintenance access is no longer possible for said persons.
A further known option for secure administration of maintenance accesses is to provide the respective network sockets for maintenance access in an area to which access is physically protected. For example, the network socket can be secured with a lockable maintenance flap or can be located in a lockable room. Such a method is, however, associated with uncertainties because a physical access protection can be overcome with little effort in most cases. In addition, this type of solution also demands significant administrative outlay, for example, for distributing and collecting the mechanical keys.